Merge pull request #462 from devlights:add-httppost-example

Add cmd/httpost/main.go

Author: devlights

cmd/httppost/main.go

@@ -0,0 +1,106 @@
+//
+// http.NewRequest() を使って HTTP POST リクエストを試してみるサンプルです。
+//
+// リクエストの発行先は JSONPlaceholder (https://jsonplaceholder.typicode.com/) を
+// 使わせてもらっています。
+//
+// REFERENCES:
+//   - https://dev.to/devkiran/make-an-http-post-request-in-go-29p
+//
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+)
+
+type (
+	Post struct {
+		UserId int    `json:"userId"`
+		Id     int    `json:"id"`
+		Title  string `json:"title"`
+		Body   string `json:"body"`
+	}
+)
+
+func (me *Post) String() string {
+	return fmt.Sprintf("Uid: %d, Id: %d, Title: %s, Body: %s", me.UserId, me.Id, me.Title, me.Body)
+}
+
+const (
+	method      = "POST"
+	url         = "https://jsonplaceholder.typicode.com/posts"
+	contentType = "application/json"
+)
+
+var (
+	appLog = log.New(os.Stdout, "", 0)
+	errLog = log.New(os.Stderr, "[Error] ", 0)
+)
+
+func main() {
+	// -------------------------------------------
+	// Create request and set headers
+	// -------------------------------------------
+
+	var (
+		body = []byte(`{"userId": 999, "title": "try-golang", "body": "try-golang/cmd/httppost"}`)
+		buf  = bytes.NewBuffer(body)
+	)
+
+	req, err := http.NewRequest(method, url, buf)
+	if err != nil {
+		errLog.Println(err)
+		return
+	}
+	req.Header.Add("Content-Type", contentType)
+
+	// -------------------------------------------
+	// Send http POST request
+	// -------------------------------------------
+
+	var (
+		client = &http.Client{}
+	)
+
+	res, err := client.Do(req)
+	if err != nil {
+		errLog.Println(err)
+		return
+	}
+	defer res.Body.Close()
+
+	// -------------------------------------------
+	// Check http status code
+	// -------------------------------------------
+
+	if res.StatusCode != http.StatusCreated {
+		errLog.Printf("http status code: %d", res.StatusCode)
+		return
+	}
+
+	// -------------------------------------------
+	// Decode response to JSON
+	// -------------------------------------------
+
+	var (
+		post    = &Post{}
+		decoder = json.NewDecoder(res.Body)
+	)
+
+	err = decoder.Decode(post)
+	if err != nil {
+		errLog.Println(err)
+		return
+	}
+
+	// -------------------------------------------
+	// Show results
+	// -------------------------------------------
+
+	appLog.Printf("status: %d, resonse: %s\n", res.StatusCode, post)
+}